The present application relates generally to the field of toilets (e.g., water closets, flush toilets, etc.). According to one aspect of the present application, a rimless toilet includes an improved jet hole (e.g., an orifice, hole, water jet, etc.) to more effectively utilize the flush water to clean the toilet bowl. Another aspect of the present application relates to an improved shelf (e.g., a ledge, terrace, bowl surface shape, etc.) for the rimless toilet that is configured to more effectively direct the flush water around the toilet bowl, and wash the bowl surface. One or both of these advantageous features may be employed in a particular toilet according to an exemplary embodiment.
Conventional toilets typically include a bowl that is configured to receive waste. Water is introduced into the bowl to wash the bowl and facilitate in transferring the waste to a drain, such as a municipal sewer drain. In view of a variety of factors, such as legislation regulating the amount of water a toilet may use per flush cycle and the cost and availability of municipal water, toilet manufacturers have tried to design toilets which have a more efficient flush cycle (i.e., the toilets use less water per flush cycle). As toilets use less and less water for a flush cycle, one challenge is to retain the effectiveness of the toilet to clean surfaces and evacuate waste from the bowl.
In toilets that include rims for directing flush water into the drain, a typical configuration includes an upper rim that may be positioned near the top of the bowl (e.g., overhanging the bowl) and that includes several holes (e.g., apertures, orifices, spray holes, jets, etc.) in an underside of the rim through which flush water may flow in order to wash the bowl and transfer any waste to a drain. One example of a conventional rim design is a box-type rim, which may have a closed, hollow cross-section through which water may flow. Another example of a conventional rim design is an open-type rim, which may have a cross-section shaped like an inverted “U.” As compared to the box-type rim, the open rim does not include a bottom wall for at least part of its length.
Toilet rims, such as box-type rims and the open-type rims, typically overhang at least a portion of the toilet bowl (i.e., usually near an upper, outward portion of the toilet bowl). Consequently, water flowing from such a toilet rim typically enters a top portion of the toilet bowl from discretely positioned holes around the perimeter of the bowl. The relatively small size of these holes reduces the energy of the flowing water, and the discrete positions reduce the overall coverage of the surface cleansing water. Additionally, water that is retained within the rim and does not flow out of the rim wash holes flows backwards to a primary jet channel. This water is effectively wasted as it does not contribute to the cleaning of the bowl surface or to bulk waste removal. Therefore, water efficiency is undesirably reduced in these toilets.
Further, the bowl surface directly underneath an overhanging closed or open rim and the underside of the rim itself may be concealed from view to a user looking down on the bowl from above. Accordingly, these portions of toilet bowl surface might be inadvertently neglected when the user cleans the toilet. As a result, waste and contamination (e.g., bacteria) may undesirably collect underneath an overhanging toilet rim.
Recently, there has been increased interest in designing toilets that do not include a typical rim for distributing water about the bowl. Some of these designs incorporate a bowl design that includes features intended to keep the water swirling about the bowl from splashing upward toward a user, such as a top portion of the bowl that curves inward toward the center of the bowl to create a “channel” in which the water will travel (see, e.g., FIG. 1A). Such features result in an “undercut” configuration for the bowl, which may undesirably increase the overall cost to manufacture the toilet bowl since additional molding steps may be required to form the undercut features. It would be advantageous to provide a rimless toilet that is configured to prevent water from splashing out of the bowl, but that does not include an undercut feature such as that described above.
Known rimless toilets typically include one or two primary orifices (water jets, jet holes, etc.) to introduce flush water into the toilet bowl. In cases where the toilet utilizes a pressurized water supply, one jet hole may be used. In gravity-fed toilets, however, two jet holes are typically used because the configuration of the toilet system may not provide adequate water pressure for one jet hole to distribute flush water around the entire surface of the toilet bowl. As an example, gravity-fed rimless toilets may include two water jets near the rear of the toilet bowl such that each jet hole may be used to wash approximately 50% of the toilet bowl (see, e.g., FIG. 1B, showing a toilet having a bowl 1 and two water jets 5 directing water outward from a manifold 3 at the rear of the bowl 1). It would be desirable from a manufacturing standpoint to provide a rimless gravity-fed toilet that utilizes only a single jet hole to introduce flush water into the bowl.
For gravity flush toilet products using two bowl wash jets, there are two typical configurations, the first is to direct both of the jets in the same direction, and the other is to direct the water in opposite directions; typically from the back of the bowl with water flowing toward the front of the bowl. Both of these configurations result in performance issues. With both bowl wash jets flow in the same direction, one of the jet feed paths must bring the wash water from the back of the bowl, and then turn the direction of the water 180 degrees with a U-turn in the flow channel. This substantially reduces flow velocity and energy that could be used to wash the bowl. With the dual opposing jet configuration, no water flow energy is lost, but wash water must be provide with a secondary means to the back of the toilet bowl between the opposing jets. This is typically done with such means as a separate nozzle, added ceramic pieces, or special hole cutting methods. These special efforts result in additional cost and complexity.
One tactic used by manufacturers of gravity-fed rimless toilets to increase the flow velocity of the flush water exiting the jet holes is to decrease the size of the jet hole. One tradeoff of employing smaller jet holes, however, is that the water flowing through the hole will have increased turbulence, thus increasing the likelihood that water will splash out of the bowl toward a user. It would be advantageous to employ a jet hole that decreases the amount of turbulence in the flush water while maintaining or improving the velocity of the flush water being introduced through the hole.
Accordingly, it would be advantageous to provide a rimless toilet design that addresses one or more of the issues discussed above, and that is relatively simple and efficient to manufacture.